The Study of Low Temperature Sintered Yttrium Oxide-riched Ceramic Shell Mold

• Main Authors: Chao-Yung Chu, 朱超勇
• Other Authors: Tseung-Yuen Tseng
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/81603751981334855053

碩士 === 國立交通大學 === 應用化學系 === 83 === The purpose of this study is to investigate the low temperature sintered yttrium oxide-riched ceramic shell mold. Because of the expensive cost and high sintering temperature (above 1600.DEGREE.), we try to add another refractory powder to improve them. In addition, the manfacturing process of the ceramic shell molds : about the composition of slurry and its rheology behavior , the control of the drying, the steps of losing wax, and the temperature control of sintering, we would discuss and optimize them. The optimal slurry for making ceramic shell molds demands high solid content, stable and sutiable viscosity state, and shear thining behavior.We add the yttrium oxide sols as the binder, methylcellouse as the polymer dispersion agent and add the buffer solution if the powder is unstable. The buffer solution is composed of acetic acid and sodium acetate, it can let the solution far from isoelectric point and keep stable longer. In our experiment the final products: there are two kinds of ceramic shell molds. The first molds sintered at 1400.degree. for 10 hours, and the strength is 950psi. The second molds sintered at 1400.degree. for 5 hours, and the strength is 1000psi. The density are 2.7and 3.5, respectly . Both of specimens are satified with the properties of shell molds.